Title : Antibiofilmogram: An innovative test for personalized treatment of pathogenic biofilm-producing bacteria
Pathogenic bacteria are characterized by their ability to adhere to a surface and form a protective biofilm, highly tolerant to antimicrobial agents. In routine medical microbiology, the classical techniques of antibiogram: agar diffusion method or liquid microdilution method are adapted to the evaluation of the activity of antibiotics on planktonic bacteria.
The minimum inhibitory concentrations and the resulting classification of strains (resistant or sensitive) allow, in most cases, to choose an effective antibiotic therapy for an acute infection. However, we have seen that in chronic infections where a biofilm is present, bacteria are able to tolerate very high concentrations of antibiotics, which can lead to therapeutic failures, despite the administration of an antibiotic therapy classified as effective by the classical methods of antibiogram. The latter are no longer systematically predictive of therapeutic success.
Indeed, the methods currently used routinely in clinical microbiology do not take into account the sessile forms potentially present in a biofilm. Knowing that 65% of human infections seem to involve the formation of a biofilm, it appears necessary today that the approaches chosen to predict the activity of antibiotics in vivo integrate the "biofilm" dimension of bacterial phenotypes found in an infectious context. We are therefore talking about a new generation of tests that can be described as antibiofilmogram.
The realization of Antibiofilmogram on clinical isolates has made it possible to highlight phenomena of inhibition and induction of biofilm formation. More precisely, aminoglycosides are able to delay bacterial adhesion. Conversely, the β-lactam family has the ability to stimulate early adhesion of microorganisms.
The clinical relevance of the Antibiofilmogram is therefore confirmed by its ability to detect the early initiation of bacterial adhesion, to select the molecules that inhibit it and to rule out those that may induce it. Combined with traditional antibiotic susceptibility tests, its application can be used to refine therapeutic strategies for the treatment and monitoring of bacterial infections.